Electrically heated hot water reservoir



Jan. 21, 1941. "r. STIEBEL ELEGTR ICALLY HEATED HOT WATER RESERVOIR 2 Sheets-Sheet l Filed Aug. 22, 1938 INVENTOR. mmdwflz'ce/ a. K m ATTOR EY.

Jan. 21, 1941. T. STIEBEL ELECTRICALLY HEATED HOT WATER RESERVOIR g5 INVENTOR fink/fife?! ATTORNE 2 Shuts-Sheet 2 Filed Aug. 22, 1938 Patented Jan. 21, 1941 itmc'rmcmy HEATEIII; HOT WATER BESEBVO ramm- Stiebel, Berlin-Tempelhoi',

Germany Application August 22, 19:8, sedat ve. 220,100

iz'cmms.

This invention relates to electrically heated 'hot water reservoirs especially adapted for home use.

The primary object of the inventionis to provide an ingenious and simple arrangement of set-v table means with an electric switch device actuated by a temperature responsive device rendered active by the temperature oi! the water in the reservoir to be heated to control and regulate the electric heat output and the heating oi! the water to two or more stages or degrees of temperature as well as regulating the rapidity-oi the heating of the water.

Furthermore, the invention is particularly adapted for use where electric current is available at diflerent schedules oi? costs or tarifls to eii'ect heating 0! the. contents or the reservoir mainly by the electric current. supplied at the 4 lower schedule of cost.

In the electric hot water heaters now in commercial use, it is possible to regulate the temperature of the water in. a-reservoir by adjusting switching mechanism oi. said heater but theswitching mechanism of such heaters are en'- closed in a casing which necessitates theremoval 0! a cover plate of said casing and the use 01'.

tools to effect the adjustment of the switching mechanism. This adjusting or the switching mechanism of the present type oif water heater will take time and permits inexperienced persons to tamper with the switching mechanism which is dangerous and undesirable. To prevent tampering of the switching mechanism by inexperienced persons, the cover plates thereof are usually sealed.

To overcome the above disadvantages of the present type of hot watenheatenthe present invention provides a simple switch to preselect the temperature a: the water in the reservoir. at which temperature. electric heating means mounted in the reservoir is disconnected or cut out of circuit with a source of electricity.

In the heaters of heretofore known types, the electric heati elements thereof have been adiusted to heat the water to a predetermined temovercome by the present-inventionby the use 0! switch mechanism interposed in the circuit of the heating element and -a thermostatically operative switch for controlling the heating element.

It is further the present practice 01' heating water in a reservoir by electric current sold at a low rate or tariilf, which occurs usually during the night when demand for electric current. is .vSllBht, to provid e heating means which will heat the water to 85 C. within theperiod at which the electric current is available at a low cost. It the user 01' the hot water desires to have water at a temperature of only 45 0., he will set the thermostatically operative switch to cut the heat ing means out of circuit with the source of electricity when the water has reached a temperature of 45 C. The heating oi! the water to a temperature of 45 C. by heating means adapted to heat the waterito 85 C. within the period a: low, cost electric current will only require half 61 said period 01' low cost. This, however, is not to the advantage of the user, because during the last half of the period 01' low cost distribution oi. electric current, the water in the reservoir cools and at the end 0! said period the water is usually cold and it will be necessary to use electric current at. the usual rate of cost, it hot water is desirable. This procedure on the part of the user is also not advantageous to the distributor of electric current because the current is only used for half the period of low cost distribution and it is in the interest'of the'distributor that the consumption of electricity during said period be uniform for the entire period of lowcost distribution. r

This defect in the present practice of heating water at low cost is overcome by the present invention by utilizing heating means having portions of diflerent heating values and connected in circuit with settable switch means adapted to be adjusted to permit the connecting oi. the different portions in circuit with the source of electricity in proper sequence, whereby there will be a uniform consumption of electricity during the period of low cost distribution.

Other objects and advantages of this invention will beset forth in the detailed description of the diflerent embodiments of the invention.

In the drawings acconipanying and forming a embodiment of the. invention wherein a pair of electric heating elements having different heating values are shown' with settable switch mechanism for preselectively connecting the heating elements to two different meters connected to a source of electricity for registering the amount of electricity consumed at different rates of cost.

Figures 4 to '7, inclusive, are diagrammatic views of the settable switch mechanism shown in Figure 3 and showingrespectively the positions 01' said mechanism to energize the heating element of low heat value through the meter for low cost electricity, to energize the heating element of low heat value through the meter for low cost electricity for agreater length of time, to energize both heating elements through the meter for high or regular cost electricity, and to disconnect both heating elements from both meters;

and

Figure. 8 is a fragmentary view of the lower portion of the water reservoir and showing means operative by the discharge of hot water from the reservoir to actuate the settable switch shown in Figures 3 to '7, inclusive, and connect the electric heating elements to the meter registering the low cost electricity. I

In carrying out the embodiment of the invention illustrated in Figure 1, there is provided a water reservoir or tank 8 having a cold water inlet pipe 9 entering and terminating in the reservoir at the bottom thereof, and a hot water discharge pipe 80 mounted in the reservoir in communication with the water in the upper part thereof. The water in the reservoir is heated to predetermined temperatures by an electric heating element H of the immersion type, as shown in my Patent No. 2,060,644, issued November 10,

1936, mounted in the reservoir by a suitable electric insulated support fixed in the bottom of the reservoir, as at l2, and adapted to carry electric conductors connected to the terminals of the heating element and extended exteriorly of the reservoir, one of said conductors being connected to one side of a source of electricity, as at i3.

The other side of the source of electricity is connected to the heating element II through thermostatically and manually operative switch mechanisms", whereby the heating of the water to a predetermined temperature is controlled by the temperature thereof and the heating of the water above said predetermined temperature is controlled by the user. The thermostatically operative switch mechanism is shown to be in the form of a mercury switch comprising a sealed tube ll containing mercury and arranged with three spaced .depressions or pockets for the mounting of fixed contacts therein, as at l 5, l6, and H. The tube I4 is pivotally mounted transversely of its longitudinal axis in the usual manner relative to the bottom oi the reservoir; so that the tube will be turned in a clockwise direction, looking at Figure 1, by a rise in the temperature of the water in the reservoir 8 through the action of a thermostat device comprising a fixed carrying casing l8 mounted in the bottom of the reservoir and extended into the reservoir centrally of the heating element II and to adjacent the upper end thereof, and a temperature expansion rod 19 engaged in the casing l8. and having one end portion extended through the bottom of the casing I8 and reservoir 8 and operatively connected to the mercury tube [4 by a coupling member 20, whereby the expansion of the thermostat-rod I9 will tilt the right hand end of the tube, looking at Figure 1, in a downward direction. I

When the Water is cold in the reservoir 8, the mercury switch tube I4 is positioned by the thermostat 'rod- IS with the mercury connecting the contacts l5 and I6, which will complete the cir cult of the heating element ll through a conductor 2| leading from the side of the source of electricity opposite to the side connected to the heating element to contact l6, and a conductor 22 leading from contact I5 to a conductor 23 of the conductors connected to the heating element H. The contact I! is also connected to the conductor 23 by a conductor 24 and manually operative switch, as diagrammatically indicated at 25 in Figure 1. The energization of the heating element by the completion of the circuit through the the reservoir to a high temperature or to a tem-- perature higher than the temperature required for moving the mercury in tube 84 from contacts i5, 06 to contacts i6, H, If it is desirable to heat the water to said higher temperature, the switch 25 is actuated to close position to. connect conductor 26 with conductor 23, and if said temperature is not desirable, the switch is actuated to open position, whereby the side of the source of electricity connected to the mercury switch is disconnected from the heating element. Should the switch 25 be actuated to closed position, the water in the reservoir 8 will be heated to a predetermined temperature which will cause the thermostat rod l9 to actuate the mercury tube l4 and position the mercury out of engagement with contact l6 and only in engagement with contact I1, whereby the circuit of the heating element l I will be broken between contacts I6 and I! of the mercury switch.

It should be understood that the temperatures of the water in the reservoir 8 at which the mercury switch tube I4 is actuated, may be varied to predetermined degrees by the form of mercury tube and the amount of expansion of the thermostat rod iii. In Figure 1, a straight mercury switch tube is illustrated but this tube may be of curved formationas shown in Figure 2. The amount of expansion of the rod l9 depends on the material used and the relative length between the rod I9 and casing l8. I

In the circuit disclosed in Figure 1, it is only possible to heat the water in reservoir 8 to two predetermined temperatures. If it is desirable to heat the water to three predetermined temperatures, the circuit disclosed in Figure 2 is used, which includes a heating element divided into portions having different electric heat output or value or a pair of heating elements of different electric heat output, as indicated at 26 and 21 in Figure 2, adapted to be mounted in the reservoir 8 shown in Figure 1, relative to the thermostat l8, l9. In the present instance the heating portion or element 23 has a heat output 01 700 watts and heating portion or element 21 has a heat output of 500 watts. The thermostat actuates a mercury. switch comprising a mercury tube 23 of curved formation and arranged with live spaced depressions or pockets 23, 33, 3|, 32 and 33 in the convex side thereof. One side of each heating portion or element 23, 21 is connected to one side of a source of electricity by the conductor l3 and the opposite side of the source of electricity is connected by the conductor 2| to a contact 34 mounted in the depression 33 and having an arcuate conductor 35 bridging the depression 3| and terminating in the depression 32. The depressions 29, 3| and 33 are arranged with fixed contacts 41, 5| and 43, respectively, connected in circuit with sides of the heating portions or elements 23, 21 opposite the sides connected to the conductor |3 by settable means S comprising a pair of manually operative switch mechanisms. Said switch mechanisms are superposed to each other, as shown in Figure 8, but are shown juxtaposed to each other in Figure 2 to clearly illustrate the electrical circuits. One oi said switch mechanisms is arranged with four equidistantly spaced contacts 33, 43, 4| 42 insulated from each other and adapted to be engaged by a rotatable contact maker having three blade leg portions 43, 44, 45 extending at right angles and electrically connected to each other, so that the contact maker will engage and electrically connect three adjacent contacts in every position thereof; The other switch mechanism is arranged with tour equidistantly spaced contacts 35 33, 43', 4|" and 42' corresponding to and in alinement with the contacts 33, 43, 4| and 42, respectively, and a contact member having three electrically connected blade portions 43', 44' and 45' correspond ng to the blade portions 43, 44

do and 45 of the first mentioned switch mechanism. The contact makers of the switch mechanisms are mounted on a common shaft with a blade of each contact maker in line with its corresponding .blade of the other contact maker. Con- 45 tacts 33 and 42' are connected to each other by a wire 43 and connected to a contact 41 mounted in the depression 23 of the mercury switch tube 23- through a wire 43 connected to said contact 41 and wire 43. The contact 43 50 is connected to a contact 43 mounted in the depression 33 through a wire 53 connected to the contacts 43 and 43. The contacts 4| and 4| are dead contacts which are not connected-to either the contacts of the mercury switch or the 55 heating elements. Contact 42 is in circuit with a contact 5| fixedly mounted in depression 3| of the mercury tube 23 through a wire 52 connected to said contacts. Contact 33' is in circuit with the heating element'or portion 23 through a wire 30 53, and contact 43' is in circuit with the heating element or portion 21 through a wire 54. It is possible by the circuits described to regulate the heating of the water in the reservoir 3, so that the water may be heated to three predetermined 65 degrees. In the illustration shown in Figure 2,

the heating element or portion 23 has an electric heat output or power of 700 watts and the element or portion 21 has an electric power of 500 watts. In the'position of the contact mako ers shown in Figure 2, the element 21 will be energized in the initial or cold position of the mercury switch tube '23 with the mercury therein in the depressions 23 and 33, by the current passing from one side of the source of electricity 75 through conductor 2| contact 34, the mercury,

contact 41, wires 43 and 43, contact 42', contact maker blades 45', 43, contact 43', wire 54, element 21 and conductor 3 to the other side of the source of electricity. It the contact makers 43, 44, 45, 43', 44', 45', remain in the position shown in Figure 2, the heating elements 23 and 21 are cut out of circuit'with the source of electricity by the next successive actuation of the mercury. switch by the temperature of the water created by heating element 21, which actuation will position the mercury in depressions 33 and 3|. The mercury in this position will close the circuit between contacts 34 and 5| of the mercury switch but in the Figure 2 position of the settable switch the circuit between the heating elements 26, 21 and the source of electricity will be open between contacts 39 and 42 of the settable switch. Therefore, in the Figure2 position of the settable switch, the water in the reservoir 3 will not be heated to a temperature higher than the heat output of heating element 21, or 500 watts in the present instance.

If it is desirable to heat the water in the reservoir to a slightly higher temperature, the heating element or portion 25 will be placed in circuit with the source of electricity by setting the contact maker blades 43, 44, 45 into engagement with contacts 4|, 42, 33, respectively, and con-. tact maker blades 43, 44', 45' into engagement with the contacts 4|, 42', and 33', so that the initial position of the mercury tube 23 with the mercury in the depressions 29 and 33 will complete the circuit of the heating element 23 with the source of electricity through conductor 2|, contact 34, the mercury, contact 41, wires 43, 46, contact 42', contact maker blades 44', 45',

contact 33, wire 53, element 26 and conductor l3. The element 23 will remain energized in all the subsequent positions of mercury switch tube 23 except the last circuit making position.- In the position of the tube 23 with the mercury in depressions 33 and 3|, the circuit will be completed through conductor 2|, contact 34, the mercury, contact 5|, wire 52, contact 42, contact maker blades 44, 45, contact 33, wire 43', contact 42', contact maker blades 44' and contact 33', wire 53, element 26 and conductor l3. In the position oi the tube 23 with the mercury in depressions 3| and 32, the circuit will be completed through conductor 2|, contact 34, arcuate conductor 35, the mercury, contact 3|, wire 52,'contact 42 contact maker blades 44 and 45, contact 33, wire 45, contact 42, contact maker blades 44', 45', contact 39, wire 53, element 26 and conductor i3. In the last circuit making position of the tube 23 with the mercury in depressions 32 and 33, the circuit is open at contact 43, as there is no contact maker blade engaging said contact 43. Therefore, the water in the reservoir 3 will be heated to a temperature commensurable to the 700 watts of the heating element 23, when the switch mechanism is adjusted to the last described position.

The water in the reservoir 3 may be heated to the highest temperature possible by the combined heat output of heating elements 23 and 21 by setting the contact maker blades 43, 44, 45 to engage contacts 42, 33, 43, respectively, and contact maker blades 43', 44', 45' to engage contacts 42', 33', 43', respectively. In the initial position of the mercury tube switch 23, the mercury will be positioned in depressions 23 and 33 and the circuit will be completed through conductor 2|, contact 34, the mercury, contact 41, wires 43 and 43, contact 42', contact maker cury switch tube 28 with the mercury either in' pockets 2|, II or 2|, 32, the current from the source of supply will be connected to contact 5| through either contact ll or conductor 25 and. the current" from contact II will travel to the heating elements 25, 21 through wire 52, contact 42, contact making blades 42, 44, contact 38, wire 45, contact 2', contact making blades 42', 44, 45', contacts 30', ll, and wires 53, '54.. In the next successive position oi the mercury tube switch, the mercury will be in pockets 32, 32 and the circuit will pass through conductor 2!, contact ll. conductor 25, the mercury, contact 49, wire 55, contact ll, contact making blades 45, 44, contact", wire ll, contact 42', contact making blades 42', 44', 45, contacts 39', Ill, wires 53, 54, heating elements 25, 21, and conductor B. When the thermostat II, II aiiected by the temperature of the water created by the heating elements 2|, 21, actuates the mercury switch tube 22 to position all the mercury in the end of the tube arranged with the pocket 33, the heating elements will be de-energized by cutting oi! the side oi the source of electricity connected to conductor 2i from-the contact 49 01' the mercury switch, as the mercury in the tube 25 will not be in engagement with either the contact 34 or conductor II.

The heating Por ions or elements 26 and 21 are disconnected from the source of electricity by adjusting the settable switch to position the contact making blades-42, l4, and 45 to en-- gage contacts 2!, II and ll, respectively, and the contact making blades 42', I4 and 45' to engage contacts 22', ll and ll, respectively, so that the contacts 42 and 42' are open;

The settable switch shown in Figure 2 is arranged with suitable indioes thereon to indicate the predetermined temperatures at which the water in the reservoir may be heated by the heating means moimted therein, whereby mistakes and incorrect connections are avoided.

The electric circuit shown in Figure 2 may be adapted for heating the water in the reservoir by electricity obtainable at a low rate 01 cost, as during the night period when public consumption is slight, by providing heating elements 28, 21 having a heat output capable of heating the contents of the reservoir 8 to the highest desirable temperature within the period of low cost electricity.

The following table sets forth the results obtained in heating water in a reservoir of 26 gallons by the four adjustable positions 0! the settable switch mechanism in the sequence described hereinbei'ore:

Heat out- Heating Heating tch position u at in time apwatts proximately Hours for registering the amoimt of electricity used at diflerent rates oi cost depending upon the time said electricity is used. This embodimentoi the invention is illustrated in Figures 3 to 7, inclusive, whcreinthe heating elements 20 and 21 are arranged as separate units with the element 28 mounted in the reservoir I in a higher plane than thefe lement 21, and the element 25 constituting an heating unit and the element 21 constituting the main or primary heating unit.

' The heating element 28 is mounted in elevated position in the reservoir I by a tubular insulated member ll fixed in the bottom of the reservoir and extended upwardly to a point intermediate the top and bottom of the reservoir. The heating element 26 is shielded from the bottom of the reservoir by a cup shaped member 50 to direct the heat of said element 25 toward the upper portion of the reservoir. The heating element 21 is mounted adjacent the bottom of the reservoir and 54, respectively.

The energization of the heating elements 28,

'21 is regulated by the temperature oi. the contents oi the reservoir I through the thermostat l8, l9 operatively connected to a mercury switch of the structure shown in Figure 1 comprising a straighttube l4 containing mercury and arrangedwith three spaced depressions or pockets arranged with flxed contacts II, II and I1. The thermostat l8, I9 is mounted in the reservoir to extend in the heatingzones of the heating elements 26, 11.

The regulation of the heating elements 25, 21 by the thermostatically operative mercury switch ll, 15, i8, i1 is manually controlled by the settable switch to heat the contents of the reservoir to two predetermined temperatures. The settable switch is of a structure similar to the settable switch shown in Figure 2 with the exception that the switch shown in Figure 3 comprises four switch mechanisms 58, 59, 80 and 5! instead of two switch mechanisms shown in Figure 2. The switch mechanism 58 is arranged with two insulated contacts 52 and 83 and a rotatable L shaped contact maker 54 adapted to engage and connect the contacts 52, II. The contact 52 is electrically connected with the terminal of heating element 25 by wire 52. Switch mechanian 59 has two contacts 56 and I1 insulated from each other and adapted to be connected to each other by a T shaped contact maker 85 coupled to the contact maker 54 with the portions 0! the contact maker 84 coinciding with the leg and a section of the cross portion oi! the contact maker 68. The switch mechanism 55 is mounted superposed to the switch mechanism 50, as

shown in Figure 8, with contacts 56 and 51 in line with contacts 52 and 53, respectively. The contact 5 is electrically connected with contact 52 through a wire 59 and electrically connected with the free terminal or heating element 21 by a wire 54. The contact 86 is also electrically connected with contact l5 of the mercury switch by a wire 1|. The contact 51 of switch 55 is electrically connected with the contact l1 of the mercury switch by a wire 12. The switch mechanism 50 is arranged with three contacts 12, 14,

st am and II and a T shaped contact maier "coupled with and extending in the same plane asthe contact makers l4 and 8 but positioned with the configurations extending at a right angle to the configurations or the contact maker. Contact J3 is electrically connected with contact ll of the mercury switch by a wire 11 and contact 13 and 15 are electrically connected. as shown at .10. The switch mechanism 69 is mounted in superposed relation to the switch mechanisms 58 and 58 with the contact 13 in line with contacts land 66, respectively, andcontact I4 in line with contacts 63 and 51, respectively. The switch mechanism 6| is arranged with tour contacts l9, 80, 8l, 82' and an- L shaped contact maker 83 coupled with the contact makers ll, 88, It and positioned wtih the-configurations thereof extending at 180 to the configurations or contact 64. switchmechanism 8| ismounted in superposed relation to the switch mechanisms '8, '8, Bl, with the contact 19 in line with contacts '2, 68, 13, respectively, contact in line'with. contacts 63, O1, 14, respectively, and contact-II in line with contact ll of switch mechanism I. Contacts, 19 and ll are permanentlyconnected by a wire 81', and contact" is electrically connected with contact ll or switch mechanism ill by a wire 84. ,The contact it is connected by a conductor 85 to a meter (not shown). connected to a source of electricity and adapted to register the electricity at a low rate .or tariff, and contact}! is connected by a conductor '6 to anotlnayre meter (not shown) connected to the same sour of electricity but registering said electricity at the normal rate or tariii. I

The switch mechanisms-58, 59, 60 and SI are adapted to be adjusted to four different positions, as shown in Figures 4 to7, inclusive, to preselect two diii'erent temperatures to which the water may be heated by the heating elements 2. and 21 in reservoir I at diflerent costs and. within diii'erent periods of time; In'the Figure 4 position of the switch mechanisms El, l9, l and II, the water is heated drom the meterregistering the low rate of electricit by heater 2'! to a low temperature, as the circuit 01' heater 21 will be opened when the mercury switch I4 is" actuated by the thermostat l8; I! to position the mercury out of engagement with'th'e contact l5 of the mercury switch, the circuit being broken at contact. 81 of the switch mechanism 50. In the Figure 5 position of the switch mechanisms, the water is alsd heated from the meter registering the low rate of electricity but to a higher temperature by the heating element 21, as the heating element 21 isenergi zed for a longer period oi time due to the fact that the circuit of said heating'element will remain close 3 until the mercury switch is actuated by the temperature of the water in theireservoir to position the mercury-out of engagement with the contact ll thereof. In the Figure 6 position of the settable switch mechanisms. the water is heated from the .meter registering the normal rate'oi cost electricity by both heating elements I, 21 to reduce the time required in heating the water to the highest temperature and there- .by keep down the cost of heating .the water when it is necessary to use the electricity'at the normal rate of cm, as during the day. In this last position 01 the settable switch mechanisms, v

the heating elements are maintained in circuit.

with the source of electricity. until the mercury in the mercury switch tube is positioned out of (I {engagement with the contact it through the acthe manner disclosed in Figure 3 will facilitate" has ceased, there is provided means adapted to tuation oithe l4 by'the rise in. temperature oi'the water. in the reservoir. In the Figure 7 position or. the, s'ettable switch mechanism, the heatingelem'ent's .26" and}! are dis-j connected from the source ot electricity and the 5 water infthe reservoir 8 will not be heated. as the circuit from the meterfor'low cost electric-I ity will bis-opened at contact 8.0"0! switch mech anism SI and the circuit from the meter for high or,-normal cost electricity will'beopened' at con- 10 tact ll of "switch mechanism", so that contact li of the mercury switch'will be disconnected from the source of the electricity; H I

- The water in-a 21gall'on reservoir will beheated by the heaters 2e and 2 1 navinsa heat 5 output or 1.5,; kw. and I kw.-, respectively, under the control ofthe, settable switchmechanisms- 58, I, I and 81, follows:

museums Heating Z= tsbleswitch g g mg element Source anisms e ens 9J0; i V I,

1 27' Inwcostmetcr. 85 27 Do.

v 85 Hand 27 High cost meter.

Bythe circuit and settableiswitch mechanism shown in Figures ste '1, inclusive, the-water in the reservoir may-ordinarily he heated'by heat-.5 0

' ing element 21 to a low temperature. from. the. low rate meter, suflicient for the usual household requirements by adjusting the settabie- 'switch mechanism ,to the Figure 4 position; It there-' I .quirements for hot water are suddenly increased,

the settable switch mechanism is adjusted to they, Figured position when the heating elements 28 and 21. are energized from normal'rate' meter, It ispossible by adjusting the settable switch mechanism. to the Figure 4 position to prevent heat lossesoi the water in'the reservoir and incrustaliion of the reservoir, and decrease the v I cost or Operation. i

I'he mounting at the heatingelement in rapid heating of the water; as the amount of water directly heated by said heating element is comparatively small, and thejportion of. water drawn oil by the discharge heating element 26'. I

To preventwaste in heating the'wa'ter while I the settable switch is adjusted-to the- Figure 6 position when the requirement for the hot water" pipe l0 isnearer the be actuated by the withdrawal of water iromthe reservoir'and adjust-the settable switch mecha- 1 -nisms 58, I9, 50, ii to disconnect the-no a1 rate. ni'eter from the circuit and connect the lpw rate meter in said -circuit.- There are two embodiments of saidmeans shown in Figure 8, but both of said embodiments are. connected in the-circuit of an electromagnet, illustrated in a genera-l way and comprising a. coil 81 and a. plunger core or armature .38, having one 'end connectedto transmission means, as illustrated in ageneral way at 89, adapted to transmit longitudinal movement of the-armature 88 -to rotary movement to'a shaft on which the contactmakers N, 88, I8 and 83' are mounted. One emvoir 8 and having at its free end acontact 92 electrically connected to one end .of the coil- 81 bya wire and adapted to engage a fixed contact 94 by pressure created in said Bourdon tube by water flowing into the reservoir 8. The fixed contact 94 is electrically connected by, a wire 95 to the side of theIsource of electricity of the electromagnet opposite to the side thereof connected to the electromagnet by a wire 96. When water is discharged from the reservoir 8, water from the source of supply will pass through the .inlet pipe 9 and actuate the Bourdon tube 9| to energize the electromagnet 81 and actuate the settable switch mechanisms 58, 59, 80, 61, to the Figures 4- or 5 position. The other embodiment of the adjusting means comprises a temperature the embodiments shown in Figure '8 may be used.

Having thus described my invention, I claim:

1. In a water heater, a water reservoir, electric heating means having difierent heating values mounted in the reservoir and directly connected to one side of a source of electricity, a multiple contact mercury switch mechanism adjustably mounted, one contact of said mercury switch mechanism being connected to the side of the source of electricity opposite the side connected to the heating means, and the other contacts being connected to difier'ent portions of the heating means, a temperature expansion rod mounted in the reservoir to be affected by the temperature or the water therein and operatively associated with the mercury switch mech-' anism to initially adjust the mercury to close the circuit of the portion of the heating means of low heating value, then open said circuit of the portion of low heating value and simultaneously close the circuit of the portionof high heating value of the heating means, then open the circult of the portion of high heating value, and then simultaneously close the circuits .of both the low and high heating portions of the heating means, and settable switch mechanism interposed in the connections between the contacts of the mercury switch mechanism and the different portions of the heating means and adaptd to select a predetermined portion of the heating means to be placed in circuit with the source of electricity by the mercury switch mechanism.

2. In a water heater, a water reservoir, electric heating means mounted in the reservoir and connected to one side of a source of electricity, a

multiple contact mercury switch mechanism having a contact connected to the opposite'side of the source of electricity and having a plurality .of contacts connected to the heating means, a temperature expansion rod mounted in the reservoir and operatively associated with the mercury switch mechanism to adjust said switch mechanism to predetermined positions corresponding to variations in temperature of the water in the reservoir, and settable means comprising a series of switches, each switch having aplurality of contacts connected in circuit with the mercury switch mechanism and heating means, and'contact makers for each settable switch adapted to be actuated in unisoninto engagement with corresponding contacts to connect predetermined contacts of the mercury" 75 switch mechanism in circuit with the heating means and heat the water in the reservoir to a predetermined temperature.

3. In an electric heater, a plurality of electric heating elements of diflerent'electric power, connected to one side' of a source of electricity, an

electric switch mechanism having a series of fixed contacts and an adjustable contact maker, a plurality of said fixed contacts being connected to the opposite side of the source of electricity, a temperature expansion rod mounted to be affected by the temperature of the heating elements and associated with the switch mechanism to adjust the contact maker to progressively connect one of the fixed contacts connected to the source of electricity with any of the other fixed contacts, and settable means to select a table switch mechanisms having contacts connected to each other and the associated contact makers adapted to be actuated simultaneously.

4. An electric heater as claimed in claim 3, wherein the contact maker of the thermostatically adjustable switch mechanism is normally positioned in engagement with one contact thereof in circuit with the source of electricity, and the contacts of the settable switch mechanisms connected to each other are connected to said contact normally engaged by the contact maker of the thermostatically adjustable switch mechanism.

5. In an electric heater, a pair of electric heating elements of difierent electric power directly connected to one side of a source of electricity, a thermostatically operative switch mechanism having a series of fixed contacts and a contact maker adjustable by a rise in temperature caused by the heating elements to connect any two adjacent contacts, and manually settable means to efiect the completion of the circuit of any or both of the electric heating elements by the actuation of the thermostatically operative switch mechanism, comprising a plurality of switch mechanisms having a series of spaced contacts and associated contact makers adapted to simultaneously engage a plurality of contacts of each series of contacts, one of said settable switch mechanisms being connected to the opposite side of the source of electricity, a second settable switch mechanism being connected to the first settable switch mechanism and connected to a contact of the thermostatically operative switch mechanism, a third settable switch mechanism being connected to the remaining contacts of the thermostatically operative switch mechanism and connected to one of the electric heating ele-' ments, and a fourth settable switch mechanism being connected to the third settable switch mechanism and the other electric heating element.

6. An electric heater'as claimed in claim 5, wherein the fourth settable switch mechanism is connected to the electric heating element of highest electric power.

'7. An electric heater as claimed in claim 5,

wherein the first settable switch mechanism is connected to the source of electricity, by two wires transmitting electricity at difierent costs;

8. In a water heater, a water reservoir, a plurality of electric heating elements mounted at different levels in the reservoir and directly connected to one side of a source of electricity, a

, pansion rod.

one side-o! a source of electricity, manually settable switch mechanism connected to the opposite side of the source of electricity and to the heating means adapted to connect different parts of the heating means in circuit with the source or electricity and heat the water to predetermined temperatures, and means operatively asmechanism when the water has been heated to a predetermined temperature.

11. A water heater as claimed in claim 10, wherein the means to adjust the manually settable switch mechanismcomprises electromagnetic means having the armature operatively associated with the manually settable switch mechanism to adjust said switch mechanism, and switch mechanism connected in the circuit of the electromagnetic means and adapted to be actuated by the pressure in the reservoir inlet to close the circuit of the electromagnetic means and adjust the manually settable switch mechanism.

12. A water heater as claimed in claim 10, wherein the means to adjust the manually settable switch mechanism comprises electromagnetic means having the armature operatively associated with the manually settable switch mechanism to adjust said switch mechanism, and thermostatically operative switch mechanism connected in the circuit or the electromagnetic means and mounted to be affected by the temperature of the water passing through the reservoir outlet whereby the circuit of the electromagnetic means is closed and the manually settable switch mechanism is adjusted.

THEODOR STIE'BEL. 

